Polyolefins are subject in many applications to degradation caused by the deleterious effects of heat and light. Many stabilizers have been employed to protect such polymers from degradation but they have not been completely satisfactory in providing protection from both heat and light degradation, and often introduce color problems. Aromatic sulfur compounds have been used as heat stabilizers for rubber and polyolefins including (5-methyl-3-t-butyl-2-hydroxyphenyl) monosulfide. Symmetrical polyhydroxy compounds such as 4,4'-thiobis (resorcinol) and the like have been used in bleaching and stabilizing wood rosin. However, such materials have not been completely satisfactory in providing both heat and light resistance to polymers exposed to heat and light, particularly the polyolefins.